Photographic material



Patented Mar. 9, 1943 Pno'roGRArmo MATERIAL Thomas S. Donovan and Walter V. Wadman, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application June 18, 1940, Serial No. 341,182

9 Claims. (01. 95-428) This invention relates to photographic agents, and particularly photographic developers in dry form or compositions in dry form adapted to be added to solutions suitable for developing photographic paper and film.

of the developer.

easily utilized.

its formaldehyde content.

to formaldehyde.

dissolve in Water.

the state or the art.

It is known to add formaldehyde to developers photographic solutions. For instance, boric acid in order to harden the gelatin or-the colloidal may be, added thereto for its advantageous effect layer in which the silver halide is dispersed. It on thecleveloped film orv paper. Potassium brois also added in order to obtain high contrast. mide may be added. Water soluble compounds Formaldehyde is a gas at ordinary temperatures 10 torestrict the swelling of gelatine or the like and when added as such to developer, it must such as citrates, sulphates and phosphates may be added at the time the developer is prepared. likewise be added thereto in solid condition. Fog Paraformaldehyde, a polymer of formaldehyde, restraining and inhibiting substances may be has been used instead of formaldehyde for these present. purposes. It has been added to the aqueous solu- The solid components including the developing tions of the developers and it has also been proagent and the aldehyde-bisulphite compound are posed that it be mixed with the solid components mixed together in suitable proportions and then However, paraformaldehyde ,may be packaged for commercial distribution. has many properties which make it objectionable It is undesirable to add a base to the dry develfor use in this manner. It has a low solubility oper since it would accelerate oxidation or deso that it is diificult to get it thoroughly .disterioration of the developing agent. solved in the aqueous developer. It polymerizes' base in the presence of moisture would cause on standing to polymers of even lower solubility decomposition of the aldehyde-bisulphite salts and from which the formaldehyde is not as with loss of the aldehyde. The base can be in- It has a strong irritating odor cluded in a separate package or may be added characteristic of formaldehyde and it volatilizes to the solution at the time it is prepared. to a certain extent in dry form to lose a part of Our new composition of matter forms the developing soluticin when added to water in the This invention has for its object to provide a presence of a base. solid photographic composition which will yield aldehyde-sulphite mixture causing it to decoman aldehyde such as formaldehyde when in aquepose into ,an aldehyde and sulphite. ous solution and which is substantially free of stance, when sodium hydroxide is the base and the above difliculties. Another object is to prosodium bisulphite is combined with formaldevide a photographic composition of matter in; hyde, the reaction is as follows: dry form which is readily soluble in cold water 3 and, when dissolved in aqueous solution in athe 5 CH2o'NaHSO3+NaOH CH2O+Na2SO3+H2O presence of a base, will yield an aldehyde, the This action takes place O When the p d dry powder being substantially free of odor due in he presence of a base so that substantially Another object is to provide no 1055 Of formaldehyde takes place in the SOIid a composition of matter in dry form which con- 40 xtur u t t is t l u r th same tains formaldehyde in chemical combinationso reason the composition of matter does not have that it does not substantially volatilize and which an odor of formaldehyde as is the case with the is in such chemical condition that it will readily I formaldehyde yielding substances heretofore em- Another Object is to Provide ployed. Strong inorganic bases such as sodium a packaged dry or solid v l p r n a nin a 5 hydroxide, sodium carbonate, etc., increase the aldehyde or formaldehyde compound WhlCh will rate of aldehyde formation and are preferred. P released solution whlch can sold 1 They are also preferred for the reason that they in dry condition. Other ob ects are to improve increase contrast v The aldehyde may be combined with alkali These and other ob ects are accomplished in accordance with our invention which includes a P bisulphlteslsuch as sodmm and potassmm dry or solid mixture of a photographic agent blsulphftes and a compound of an aldehyde with a bisulphite. Thamventlon 15 of partlcular Value m connec' We have discovered that when this mixture is Wlth Phenol type developers h dissolved in water in the presence of a base, the qumone Ortho catechol para'ammophenol and aldehyde-bisulphite compound is decomposed to release aldehyde in the solution. At the same time, sulphite is released in the photographic solution where it acts to protect against oxidation in known manner.

The solid mixture may contain the well-known materials which act to improve the action of Also, the

The base reacts with the For inits salts, monomethyl para-aminophenol sulfate and chlorhydroquinone.

While we have described our invention as being particularly valuable for preparing developing compositions, it is applicable to the preparation of solid compositions which upon dissolving in water yield solutions which affect a photographic image. For instance the solid preparation may comprise the aldehyde-bisulfite compound and an intensifying agent. Although formaldehyde is preferred, other aldehydes such as acetaldehyde can be combined with the bisulfite. Water soluble aldehydes are best foraqueous developers.

In the following examples, which illustrate the method of compounding the compositions of matter and preparing developing solutions, we have given examples of how the dry compound is added to the developing solution in the presence of a base. However, our invention applies only to the solid material containing the developer and formaldehyde-bisulphite mixture and does not cover the aqueous solution or the base contained therein.

Example 1 A solid granular mixture is prepared from the following:

Grams Sodium bisulphite 1.90 CHzO-NaHSOz 37.00 Boric acid 7.50 Hydroquinone 22.50 Potassium bromide 1.57

Example 2 A solid granular or powdered mixture is prepared from the following:

Grams Sodium bisulphite-; 1.90 CHzO-NaI-ISOa 37.00 Boric acid 7.50 Hydroquinone 22.5 Potassium bromide 1.57

"To prepare a developing solution from this composition it is added to 27.70 grams sodium carbonate in aqueous solution and water is added to make one liter.

Example 3 Grams Sodium bisulphite 2.18 CHzO-NaHSOs 41.8 Boric acid 8.5 Hydroquinone -1 25.6 Potassium bromide 1.78

To prepare a developing solution from this solid mixture it is added in the proportions given to a solution of 10.04 grams sodium hydroxide. Wa-

ter is added to make one liter.

Example 4 A solid powdered mixture of the following is prepared:

Grams Sodium bisulfite 2.18 Acetaldehyde-sodium bisulfite 46.9 Boric acid 8.5 Hydroquinone 25.6 Potassium bromide 1.78

To prepare a developing solution the foregoing mixture and 10.44 grams of sodium hydroxide are added to water to make one liter of solution.

Our invention has the particular advantage that developers containing aldehydes and particularly formaldehyde can be quickly prepared in a simple manner without the disadvantage of extra manipulations such as adding formaldehyde or dissolving paraformaldehyde. It has great solubility, substantially no odor and a long exhaustion life. It has the outstanding advantage that sodium sulphite or equivalent materials need not be added. However, it is to be understood that such materials may be present, if desired.

What we claim is:

1. A composition of matter in solid or powder form, adapted to form a photographic solution containing free aldehyde in quantities sumcient to act as a hardener and a sulphite when dissolved in water in the presence of a base, comprising a photographic agent which will affect a photographic image and a compound of an aldehyde with a bisulphite.

2. A composition of matter in solid or powder form, adapted to form a developing solution containing free aldehyde in quantities sufilcient to act as a hardener and a sulfite when dissolved in water in the presence of a base, comprising a photographic developing agent and a compound of an aldehyde with a bisulfite.

3. A composition of matter in solid or powder form adapted to form a developing solution containing a free aldehyde in quantities sufficient to act as a hardened and a sulflte when dissolved in water in the presence of a base, comprising a phenolic developing agent and a compound of an aldehyde with a bisulfite.

4. A packaged composition of matter in solid 1' powder form which is stable over extended eriods of time and which is adapted to form a developing solution containing free formaldehyde in quantities sufiicient to act as a hardener and a sulphite when dissolved in water in 45 the presence of a base, comprising a photoghaphic developing agent and a compound of formaldehyde with an alkali metal bisulphite.

5. A composition of matter in solid or powder form adapted to form a developing solution containing free formaldehyde in quantities sufficient to act as a hardener and a sulphite when dissolved in water in the presence of a strong inorganic base, comprising a photographic developing agent and a compound of formaldehyde with an alkali metal bisulphite.

6. A composition of matter in solid or powder form, adapted to form a developing solution containing free formaldehyde in quantities sufficient to act as a hardener and a sulphite when dissolved in water in the presence of a base, comprising a phenolic developing agent and a compound of formaldehyde with a bisulphite. Y

7. A composition of matter in solid or powder form adapted to form a developing solution containing free formaldehyde in quantities sufficient to act as a hardener and a sulphite when dissolved in water, in the presence of a strong inorganic base, comprising a phenolic developing agent and a compound of formaldehyde with an alkali metal bisulphite.

8. A composition of matter in solid or powder form adapted to form a developing solution containing free formaldehyde in quantities sufficient to act as a hardener and a sulphite when 3 a sulphite when dissolved in water in the presence of a. base, comprising a photographic developing agent and a compound of an aldehyde with an alkali metal blsulphite.

THOMAS S. DONOVAN. WALTER V. WADMAN. 

